Mark Twain Cave - Hannibal MO
Posted by: 
PeterNoG
N 39° 41.315 W 091° 19.902
15S E 643054 N 4394524
The 1890 man made entrance of the Mark Twain Cave System is located just below the natural "discovery" entrance which is still visible.
Waymark Code: WM3JFW
Location: Missouri, United States
Date Posted: 04/12/2008
Views: 67
This cave was discovered in 1819 or 1820 by Jack Sims when a dog chased an animal into a hole. The first man made entrance was made some time after that and many including Samuel Clements investigated the cave passages. There are many miles of passages mapped. In 1849, the cave entrance was locked with a wooden door for a while.
Mark Twain (Samuel Clements) referred to these caves extensively in
The Adventures of Tom Sawyer which was published in 1876.
In 1886, it was opened to public tours and became Missouri's first show cave. It has been open to the public continuously since 1886 and in now open year round except Thanksgiving and Christmas Day.
There is a second indoor entrance in the gift shop that is used during inclement weather (and used as an exit for all tours).
The cave is a Registered National Landmark.
More info on the cave (
visit link)